More carbon-saturated and substantially denser than typical terrestria

Question

More carbon-saturated and substantially denser than typical terrestrial worlds, planets dubbed "carbon super-Earths" have long perplexed astrophysicists because such compositionally exotic bodies would not be anticipated to populate ancient galactic halos, where most stars are primitive and metal-poor.  A prevailing hypothesis holds that these diamond-layered planets coalesced when two long-established, carbon-enriched planetesimals collided and fused into a single, more massive body . Ramirez has advanced a competing model, however, contending that in quiescent stellar neighborhoods-where the ambient density of planetesimals is so attenuated that binary collisions occur too seldom to generate the observed abundance of carbon super-Earths-these anomalous worlds arise instead through multi-body gravitational capture. She proposes that a planetesimal already locked in a binary pairing constitutes a substantially  more gravitationally conspicuous target  for a third drifting body or even another binary system. Once this hierarchically nested configuration stabilizes, resonant close approaches among the captured bodies could trigger any two to coalesce into a carbon super-Earth. Ramirez's framework makes a testable prediction: each carbon super-Earth so formed should retain a distant bound companion-a signature that, she notes, has been borne out by radial-velocity observations of numerous such planets in the Kepler-192 system.   1 
In the context of Ramirez's alternative model, the phrase " more gravitationally conspicuous target " is employed chiefly to account for why a

A. carbon super-Earth would stand a greater chance of colliding and merging with another planetesimal than would a typical terrestrial world.
B. binary pair of planetesimals would be more apt to encounter other drifting bodies than would the typical carbon super-Earth.
C. binary pair of planetesimals would be more susceptible to gravitational interaction with passing bodies than would a solitary planetesimal.
D. carbon super-Earth would be more liable to gravitationally interact with a binary pair than it would with a solitary third planetesimal.
E. solitary third planetesimal would have a greater probability of encountering a binary pair than it would of encountering a carbon super-Earth.

2

On the basis of the passage, which of the following can properly be concluded regarding carbon super-Earths?

A. They are descended from protoplanetary bodies that are more carbon-saturated and substantially denser than typical terrestrial worlds.
B. They are consuming their nuclear fuel at a rate that exceeds that of other planetary types detected in ancient galactic halos.
C. They predate the majority of other planetary varieties residing within the same stellar neighborhood.
D. They occur with lower frequency in quiescent stellar neighborhoods than do binary-planetesimal pairings.
E. They typically derive from the most ancient planetesimals among those populating old galactic halos.

3

According to the passage, what consideration is offered as a reason to question the hypothesis introduced in the second sentence?

A. A disparity between the incidence of planetesimal mergers in certain quiescent stellar neighborhoods and that in other, comparable quiescent neighborhoods.
B. A disparity between the density and carbon enrichment of carbon super-Earths generated by one formation mechanism and the density and carbon enrichment of those generated by an alternative mechanism.
C. A disparity between the frequency of planetesimal collisions in quiescent stellar neighborhoods and that in dynamically active, high-density stellar neighborhoods.
D. A disparity between the carbon enrichment and density of ancient solitary planetesimals and those properties in carbon super-Earths.
E. A disparity between the rate at which solitary planetesimals collide in certain stellar neighborhoods and the number of carbon super-Earths actually observed in those same neighborhoods.

Source: my elaboration!

ReetArora · Answer

Found this one a bit tough!

heyitsmepearl · Answer

Summary of the passage-
Carbon super earths (CSE) are present in ancient galactic halos. This puzzles scientists because these halos are where most stars are primitive and metal-poor (Which tell us that these CSEs are neither primitive nor metal-poor).

Also given about CSE- Carbon saturated, denser than typical terrestrial worlds, diamond layered

Hypothesis for formation- two carbon enriched planets collided and fused into CSE

Problem with hypothesis according to Ramirez- binary collisions rarely occur, which is inconsistent with the number of CSEs.

Ramirez's hypothesis for formation-multi-body gravitational capture- a pair of planets has more gravitational force for a third body/planet to join them. More keep joining till this becomes a system and then stabilizes. Since the planets are close in this system, they collide and become CSE. So, every CSE will have a companion.

(for ease- planets= planetesimals)

Q1- In the context of Ramirez's alternative model, the phrase "more gravitationally conspicuous target" is employed chiefly to account for why a

By saying that a binary pair has more gravitational force to pull a third body, we mean that a single may not have been able to do it but together they can. By evaluating the gravitational pull of the binary pair, we are hypothesizing about the formation of CSEs other than the mentioned prevailing hypothesis.

A. carbon super-Earth would stand a greater chance of colliding and merging with another planetesimal than would a typical terrestrial world.- CSE colliding? The entire passage is about two planets colliding to form a CSE.
B. binary pair of planetesimals would be more apt to encounter other drifting bodies than would the typical carbon super-Earth.- again the idea is not that a binary pair is more probable of encountering a drifting body than a CSE. 
C. binary pair of planetesimals would be more susceptible to gravitational interaction with passing bodies than would a solitary planetesimal.- exactly, a single planet probably doesn't have that strong a pull but two of them together do.
D. carbon super-Earth would be more liable to gravitationally interact with a binary pair than it would with a solitary third planetesimal.- We are not talking about CSEs interacting with planets but rather the planets forming the CSEs.
E. solitary third planetesimal would have a greater probability of encountering a binary pair than it would of encountering a carbon super-Earth.- there is higher probability of occurrence of binary pairs than there is occurrence of collision and fusions of carbon-rich planets.

Q2- On the basis of the passage, which of the following can properly be concluded regarding carbon super-Earths?

A. They are descended from protoplanetary bodies that are more carbon-saturated and substantially denser than typical terrestrial worlds.- at first I rejected this since "protoplanetary" is not mentioned anywhere in the passage. Everything else about carbon saturated and density is mentioned. But as you go through the rest of the options, I am able to eliminate those more easily than I can this one. 
B. They are consuming their nuclear fuel at a rate that exceeds that of other planetary types detected in ancient galactic halos.- we never even remote talk about nuclear fuel in the passage.
C. They predate the majority of other planetary varieties residing within the same stellar neighborhood.- This is opposite of what is mentioned in the passage. In the 1st sentence, the author is saying that the scientists did not expect CSEs to exist in these halos where most stars are primitive and metal-poor. So CSEs are neither primitive nor metal-poor.
D. They occur with lower frequency in quiescent stellar neighborhoods than do binary-planetesimal pairings.- binary pairing was never compared to the number of CSEs. The occurrence of binary pairing was compared to the probability of two carbon-rich panels colliding to form a CSE.
E. They typically derive from the most ancient planetesimals among those populating old galactic halos.- "most ancient" is extreme. The prevailing "hypothesis" was that two "long-established" planets collided to form CSEs. Long established does not mean most ancient. Even if it means most ancient, we cannot infer this- it is a hypothesis.

Q3- According to the passage, what consideration is offered as a reason to question the hypothesis introduced in the second sentence?

The reasoning was that there are many more CSEs than there are collisions.

A. A disparity between the incidence of planetesimal mergers in certain quiescent stellar neighborhoods and that in other, comparable quiescent neighborhoods- We never compared two neighborhoods.
B. A disparity between the density and carbon enrichment of carbon super-Earths generated by one formation mechanism and the density and carbon enrichment of those generated by an alternative mechanism.- We never questioned the density and carbon enrichment of CSEs. CSEs are carbon saturated and dense is a fact.
C. A disparity between the frequency of planetesimal collisions in quiescent stellar neighborhoods and that in dynamically active, high-density stellar neighborhoods.- first past is perfect but we never spoke about the latter.
D. A disparity between the carbon enrichment and density of ancient solitary planetesimals and those properties in carbon super-Earths.- Like option B- We never questioned the density and carbon enrichment of CSEs. CSEs are carbon saturated and dense is a fact.
E. A disparity between the rate at which solitary planetesimals collide in certain stellar neighborhoods and the number of carbon super-Earths actually observed in those same neighborhoods.- that's it

More carbon-saturated and substantially denser than typical terrestria

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More carbon-saturated and substantially denser than typical terrestria

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